PDeltaDalitzKrivoruchenko.cc

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//
// Dalitz decay following
// Eq. 2 from  Comment on delta radiative and Dalitz decays.
// M.I. Krivoruchenko (Tubingen U. & Moscow, ITEP) , Amand Faessler (Tubingen U.) . Apr 2001. 5pp.
// Published in Phys.Rev.D65:017502,2002.
// e-Print: nucl-th/0104045 (Ref21)
//
//                                  Author:  I. Froehlich
 
 
#include "PDeltaDalitzKrivoruchenko.h"
 
PDistribution *PDeltaDalitzKrivoruchenko::Clone(const char*) const {
    //clone the object
    return new PDeltaDalitzKrivoruchenko((const PDeltaDalitzKrivoruchenko &)* this);
};
 
PDeltaDalitzKrivoruchenko::PDeltaDalitzKrivoruchenko(const Char_t *id, const Char_t *de, Int_t key) :
    PDalitzDecay(id, de, key) {
 
    //Constructor
} ;
 
Bool_t PDeltaDalitzKrivoruchenko::FreezeOut(void) {
    formfactor_model =
    GetSecondaryModel("formfactor");
    return kTRUE;
}
 
double PDeltaDalitzKrivoruchenko::dGdM(const int& id, const double& m, const double& ecm) {
    //dGdM from Wolf expression:
 
    double dgdm = 2.*alpha/(3.*TMath::Pi()*m);
 
    if (m<mass_ee || m>ecm-mass_x) return 0.;
//    cout << m << ":" << ecm << endl;
 
    double mn = mass_n;
    if (id==Delta_plus || id==S11_plus)
    mn = mass_p;
 
    double ff = 2.7*2.7;
 
    if (formfactor_model)
    ff=formfactor_model->GetWeight(m,ecm);
 
    dgdm *= (alpha/16.) *
    (ecm + mn) * (ecm + mn) / (ecm*ecm*ecm * mn*mn) *
    sqrt((ecm+mn) * (ecm+mn) - m*m) *
    sqrt(
        ((ecm-mn) * (ecm-mn) - m*m) *
        ((ecm-mn) * (ecm-mn) - m*m) *
        ((ecm-mn) * (ecm-mn) - m*m)
        ) * ff;
 
    //   cout << dgdm << endl;
 
    return dgdm;
 
}
 
ClassImp(PDeltaDalitzKrivoruchenko)